Question

31.(-18)+ 31. (-81)-31

-48+48.(-78)+48.(-21)

-75.(18-65)-65.(75-18)

29.(19-13)-19.(29-13)

13.(23+22)-3.(17+28)

(-25).21.(-2)².(/3/).(-1)²ⁿ⁺²(nEN*)

Answer 1

31.(-18) + 31.(-81) - 31

= 31.(-18 - 81 - 1)

= 31.(-100) = -3100

-48 + 48.(-78) + 48.(-21) = 48.(-1 - 78 - 21) = 48. (-100) = -4800

-75.(8 - 65) - 65.(75 - 18) = -75.18 + 75.65 - 65.75 + 65.18 = 0

29.(19 - 13) - 19.(29 - 13) = 29.19 - 29.13 - 19.29 + 19.13 = 0

13.(23 + 22) - 3(17 + 28) = 13.25 - 3.45 = (10 + 3).25 - 3.45

= 10 . 25 + 3.25 - 3.45 = 10.25 - 3.(45 - 25)

= 250 - 3.20 = 250 - 60 = 190

(-25).21 . (-2)².(|3|). (-1)^{2n + 2} (n \(\in\)N*)

= (-25. 4) . (21.3).1

= -100. 63 = -6300